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Oct. 23, 1928. 1,688Q805 G. O. DEG EN ER ADDING ATTACHMENT FORTYPEWRITING MACHINES Filed June 10, 1926 5 Sheets-Sheet 1 Dec.7. IBM-HA41 Randolph SHLW.

MnACflean 3526 GeorgiaAve. ,NW.

Oct. 23, 1928. 1,688,805

- G. o. DEGENER ADDING ATTACHMENT FOR TYPEWRITING MACHINES Filed June10. 1926 Oct. 23, 1928.

' 1,688,805 G. O. DEGENER ADDING ATTACHMENT FOR TYPEWRITING MACHINESFiled June 10, 1926 5 Sheets-Sheet 3 Oct. 23, 1928.

G. O. DEGENER ADDING ATTACHMENT FOR TYPEWRITING MACHINES Filed June 10,1926 5 Sheets-Sheet 4 Oct. 23, 1928.

1,688,805 G. O. DEGENER ADDING ATTACHMENT FOR TYPEWRITING MACHINES FiledJune 10, 1926 5 Sheets-Sheet 5 verdizr 6.0.D ener' lzyhll; A

Patented Oct. 23, I928.

UNETED STATES 1,688,805 PATENT oFricE.

GUSTAVE O. DEGENER, OF NEW YORK, N. Y., ASSIGNOR TO ROYAL TYIEWRITERCOM- PANY, INC., OF NEYV YORK, N. Y., A CORPORATION OF NEW YORK.

ADDING ATTACHMENT FOR TYPEWRITING IvIAGHINES.

Application filed June 10, 1926.

This invention relates primarily toan adding attachment for typcuritingmachines of the general character shown in my prior Patents, 1,633,242,June 21, 1927, and 1,624,318, April 12, 1927. Many portions of themechanism shown in the prior applications remain unchanged in the resentattachment and are not illustrated and described herein except so far asis necessary for a clear disclosure of the features of the invention. IA

Certain features disclosed and not claimed in this application areclaimed in divisional applications Serial Nos. 194,132, 194,133, and194,134, filed iday 25, 1927.

The invention is embodied in alt-attachment which can be readilyattached to and detached from the frame of the typewriting machine andrequires substantially no change in the construction of said typewritingmachine. 'Ihe adding mechanism is operated only when the carriage of thetypewriter enters the adding zone and may be easily disconnected fromthe carriage so that writing may be performed in the adding zone ifdesired without operating the adding attachment. The whole attachment islocated at one side, of the machine and does not obstruct the line ofsight of the paper, nor interfere in any wayv'with the usual operationof any of the typewriting .instrumentalities.

The invention is illustrated as applied to the well known Royal standardmachine, but it is to be understood that it may be applied to any of thestandard commercial machines by making minor changes in the connectionsand Without making any changes in the structure of the adding mechanism.itself.

This computing attachment is designed primarily for billing purposes andcan be employed wherever this class of work is to be performed. Inmaking out such bills or statements, the va rious items arewrittemeachwith date, name of article, etc., and the carriage then moved preferablyby tabulating mechanism, to-the first computing zone Where the separateamounts are written, one under the other. At, this time these amountsare set up in the column totalizer, the figures of which will at anytime show the sum of the detailed items written.

\Vhen a bill is finished it is desired to write the total in a secondcolumn and the carriage is moved to bring the paper in position to writethe sum in this column and also bring the computing mechanism into thesecond Serial No. 114,950

computing zone. The sum is then Written, being copiedfrom the figuresappearing in the column totalizer and it is simultaneously set up in thegrand totalizer. The carriage is then returned to initial position tobegin writing of the succeeding bill.

In preceding devices of this general charactcr there have been numerouschances of error which have given rise to-many objections. Unless theoperator correctly copies the total from the column totalizer, the grandtotal appearing in the grand totalizer will obviously be wrong and thecolumn totalizer may not be cleared'for beginning the writing of thesucceeding bill. A v i The prior applications fabove referred to haveovercome these objections indifferent manners. In application No.736,896, means is provided which prevent the return of the carriage intoposition to begin a new line'of writing until the 7 total has beencorrectly copied and the column register cleared. This however, didnotprevent the occurrence of the error andbnly'calledftheoperatorsattention thereto after thejen tire total had been written. fMo reover,in thatdevice the column totalizer was cleared by thecopying of thetotal and at'theisame time tlia'tit wasentered into the grandtotialiize'r, and ifanerror was made in entering the: number',}obvionslyj the column totaliz erwould not be cleared. 1 y i Theconstruction disclosed in-(application No. 14,315 had in part theobjectof preventing the occurrenceof said errors and disclosed twoformsilrfoneof which incorrect key could not be depressediwhenl thetotal is being copied from the column totalizer and the register was inthe second computing zone. In the second f0rm,a-' key could be depressedbut would not return tooperative position if it happened tobe anincorrect key. In connection with both 'forms means was provided forclearing thecolumn totalizer by the return movement of the carriage tobegin writ ing of a new bill.

This general method of clearing thecolumn totalizer is retained in thepresent construc tion and is therefore not illustrated in detail herein.An error check mechanism of a new type has been designed in which theoperation of a key lever that is incorrectly depressed is not interferedwith and said key may be fullydepressed and return fully to normalposition However, if such an incorrect key has been operated, themechanism will be locked and the operator will find it impossible todepress the succeeding key. It will, therefore be necessary for him tocorrect the error before proceeding with the writing of the remainder ofthe total.

This invention also includes an automatic means which prevents the errorcheck from becoming effective unless an item has been written in thefirst computing zone and entered into the. column totalizer. Itsometimes happens that the invoice comprises a single item which iswritten only once in the second computing zone and entered directly intothe grand totalizer. At this time there is nothing to copy from thecolumn totalizer which stands at zero and obviously if the error checkmechanism were effective it would interfere with the writing of thisitem in the second computing zone.

Another object of the invention comprises means for locking all the keysunless the totalizer is correctly positioned to receive the impulse fromthe master wheel. The means also forms a decimal lock which preventswriting in the spaces provided for commas and periods in the writing ofnumbers and therefore no additional decimal lock is necessary.

A further object of the invention resides in the employment of a numeralwheel aligning pawl which worksdirectly upon the totalizer wheel -threeor four spaces to the left of the master wheel. This pawl is normally indepressed o'r'inoperative position.

The invention also includes the provision of ana'dd and subtract shiftlever on the left handside of the typewriter frame, where it is moreconvenient to the operator, and also connections whichautomatieallyrestore this leverto add positi'onwhenever' the carr iz'v-eis returnedfaftr an item has been written in the second computing zoneand therefore entered into the grand totalizer.

Further objects of the invention will be apparent from the followingdetailed descriptionland the appended claims.

In the drawings:

Figure 1 is atop plan view of the attachment in position upon atypewriting machine conventionally illustrated, and also shows a sampleof the character of work which the invention is particularly adapted toperform.

Figure 2 is a detached view showing the train of connections fromth'eadd and subtract lever at the left hand side of the kev board to theadd and subtract lever of the totalizer and the carriage o erated meansfor returning the same to add position.

Figure 3 is a partial fore and aft section through the mechanism withparts in elevatron.

Figure 4 is a similar view with parts omitted and additional featuresillustrated.

Fig. 4 is a detail view of certain parts of the mechanism Shown in Fig.4.

Fig. 4" is a detail view of certain other parts shown in Fig. 4.

Figure 5 is a side elevation of the non-add key and parts cooperatingtherewith.

Figure (3 a front elevation of the shift ing frame of the error checkmechanism.

Figure 7 is a vertical section on the line 7-7 of Figure 6.

Figure 8 is a fragmentary view showing a part of the means for lockingthe kevs unless the totalizer is correctly positioned.

Figure 9 is a perspective view of a portion of this means.

Figure 10 is a perspective view of the rockin; frame forming a part ofsaid locking ll'KllnS.

Figure 11 is a side elevation of a second rocking fra me alsocooperating with said means.

Figure 12 is a front 'iew of the frame shown in Figure 11.

Figure 13 is a rear elevation showing the travelling totalizer andpartsofthe error check mechanism operated thereby, whereby said error checkis rendered effective when the register enters the second computingzone. I

The invention has been illustrated inconnection with a Royal standardmachine, although it is capable of application to any of the variouscommercial typewriters. The typewriting mechanism itself has beenillustrated only conventionally. since this precise structure forms nopart of the invention. 'Ijhere is shown the machine frame A, a carr ageB supporting the platen C, type bar mechanism D, ribbon mechanism E. anda key board F provided with numeral keys G having levers H. All of theseparts may be of any suitable or desired construction.

The attachment proper comprises a casing 1 the front portion of which isnarrower than the rear portion, said casing being formed by a left handside plate 2, an intermediate plate 3, which forms the rightside of thefront narrow portion, and a right'hand side plate 4. These plates aretied together. (see Figure 3) by a rear transverse member 5 havingshelves 6 and 7, by a front transverse member 8 having a shelf 9, and byrods 10 and 11 upon which travels the register 12. Other suitable tierods may be employed as shown in my rior applications or as foundnecessary or esirable. Suitable top and bottom plates are also provided.

Suitably mounted and underlying a p0rtion of the typewriter key boa-rd Fis a series of ten rock shafts 13 positioned in vertical pairs. Eachrock shaft is provided at its left end with a rearwardly extending crankarm 14 connected by a link 15 to the corresponding key lever H. Anupwardly extending crank arm 16 is attached to the right hand end ofeach rock shaft and this crank arm is pivoted at its upper end tosliding bar 17.. It will Hip be noted that the crank arms 14 and 16 areso arranged that the proper movement will be given the bars 17notwithstanding the fact that some of the rock shafts 13 are arrangedfurther from the key stems G than the others.

Each of the sliding bars 17 rests upon a support 18 near the rear endthereof. A slot ted sheet metal member 19 is supported from the framebar 8 and bent at its lower end into a substantial cylinder in which areplaced metal balls 20 so that the balls may be separated widely enoughto permit the passage of only one bar. Each bar has a projection whichpasses between said balls when the corresponding key lever is actuated.

When the sliding bars are operated they act to set up in the computingmechanism carried by the travelling register 12, numbers coirespondingto the keys depressed. This mechanism in itself is substantially thatdisclosed in my prior applications and need not be described in detailhere. A series of cam gears 21 mountedupon a shaft 22, each have gearteeth 23 adapted to mesh with rack teeth 24 on the rear end of the bars17. Each cam gear has aflixed to' one side thereof two cams 25 and 26. Asheetmetal member 27 has one edge bent about a pivot rod 28 and is fastthereon to turn therewith. VVhen one of the gears 21 is rotated by anoperation ofthe sliding bar-17 the upper end of the cam 26 will contactwith the member 27 and rock the shaft 28, together with anj-arm 29extending from one end thereof. This arm carries an offset or pin 30normally in enga'gement with the lower end of a lever 31-which ispivoted on a stud 32 carried a member 33 fast'to' the shelfafi; 5 51.13?i 11 The rotation of the cam gears will operate to set up the propernumber through a train of mechanism such as disclosed in my priorapplications? henthe cam gear'h'as been moved until the member 27 'slipsoflf the lower end of the cam 26 the shaft 28being returned to itsnormal position by the usual spring, will .cause the pin to contactsharply with the end of the lever 31. The upper arm 34 of this lever isnormally in contact with a lug 35 on a lever 36 pivoted at 37 and havinga detent pawl 38 in position to engage the teeth of one of the wheels 39of the totalizer, which wheel is three or four spaces to the left of theusual master wheel. A sprin 40 attached to the lug 35 and to the shelf 6normally holds the pawl 38 out of engagement with the totalizer wheel.However, when the lever 31 is moved sharply asabove mentioned the pawlwill move into engagement with said wheel and prevent the same againstoverthrow or displacement; At this t me the return move ment of the camgear 21 begins and the other end of the cam 26 engaging the member 27rocks the shaft 28 and arm 29 in the opposite direction. therebypositively moving the lever 31 and thereby holding the detent 38 inengagement with the wheel 39 until the return movement of the cam gear21 and the hey lever has been completed.

The rack 41 carried by the travelling totalizer carriage 12 meshes withthe pinion 42 on a shaft 43 and this shaft is adapted to be moved fromthe movement of the typewriter carriage in the manner disclosed in myother applications. This causes the totalizer carriage to havestep-by-step movement corresponding to the step-by-step movement of thet vpeu-riter carriage whenever the typewriter carriage enters thecomputing zone.

One object of the present invention is to provide a. means whereby allkeys are locked unless the totalizer is in correct position to receivethe impulse from the master wheel. This mechanism also acts as a decimallock to prevent. writing of numbers in the spaces periods in a number.

A universal frau'ie 44 is carried by arms/45 and 46 which are mounted ona shaft 47 carried in the side bars2'and 3 of the frame usually emplovedfor writing commas and work. The rearends of the sliding bars'17 engagethis universal frame 44 sothat it will be rocked each time the numeralkey is depressed. A spring-'48 attached at one end to the arm 45 and atthe other end to a/fixed portion of the frame 49 tends to return'theoffset end 55.

This offset rests against-the free end of a wire spring 56 the other endoffwhichis' attached by a screw 57 to a second rocking frame 58 (Figure10) also mounted on: the

pivot shaft 53. This frame 58 has a side member 59 and a second sidemember 60. The member 59 hasian upwardly est-ending arm 61 with arounded end whicl'r'engages between the two portions of a stop member 62in the form of an open ended loop to thereby limitthe movements of theframe 58 in each direction.

The side of this frame 5S'has an upwardly extending arm 63 which isconnected by a link 63 to a slide 64 (Figure 8) which is mounted toslide in grooves on a support 65 which is carried by a bracket- 66 fromthe cross bar 5. A pawl 67 is pivoted on a short stud 68 carried by theslide- 64 and is normally held in central position by two mem bers 69,one of which is shown in Figure 9. which are pivoted on a common pivot70 and normally drawn toward each other by coil springs 71, the ends ofwhich engage in notches 72 in the members 69. The rounded ends of thesemembers engage on opposite sides of the pawl 67 and normally hold it inits central position, although allowing it to move from one side or theother against the tension of the spring 71.

A bracket 73 on the totalizer carriage carries a rack member "('4 whichis provided with teeth 75. These teeth are arranged a proper distanceapart for the numerals and are separated by wider spaces wherever acomma or a period would naturally come in the writing of a number.

WVhen a key is actuated the universal frame 44 is operated from thesliding bar 17 and this results in rocking the frame 52 and through thespring 56 also rocks the frame 58. The rocking of the frame 58 throughthe arm 63 and link 03 moves the slide 64 with the pawls 67 toward therack bar 74 and the teeth 75 thereof. If the totalizer carriage is inthe proper position for the setting up of the number corresponding tothe actuated key. the pawl 67 will directly engage with one of the teeth75 and thereby the further movement of the slide 64 and the arm 63 ofthe rocking frame 58 will be prevented. Since the rocking frame cannotmove any farther the frame 52 will continue to move and the spring 56will be tensioned during such movement. The number will therefore beprinted and set up in the totalizer inthe usual manner However, if, thepawl 67 passes into one of the spaces-between theteeth -75, which meansthat the totalizer is not in proper position or that it is in suchposit-'ionthata comma or period should be written, the movement ofthe'frame'58 will not be stopped but will continue andthis, .willswing-the arm 76- downward .into thepath-of the unive-rsal'frame 44 andstop the movement thereof beforethe frame has moved far; enoughto set upthe number in-the'totalizenor toprint from the typewritcrkey,

a It is sometimes desired to write rin the computing zone withoutsetting up numbers 111 the totalizer and there is accordingly provided anon-add-key 77 I which is pivoted at. 78 and normally drawn in onedirection by spring 79. The rear end of this key is pro,- vided with anoffset 80 extending to one side thereof. \Vhenever this key is depressedthis offset is moved up sufficiently to be'iu the path of an arm 81carried by the rocking frame 58. Therefore, operation of this rockingframe will bezprevented bythe engagement of the arm 81 withthe'offsetend 80 of the non-add lever, regardless of the relative position of theregister.

The devices by which the mechanism may be set for adding or subtractingare or may be substantially the same as shown in my prior applicationsbut are actuated in a somewhat different manner. A short lever 82 whichcontrols the shifting from add to subtractposition and vice versa, isconnected by a link 83 to an upstanding arm 84 of a threearmed leverpivotedat 85. One arm 86 of this lever is connected by a link 87 to anarm 88 extending from one end of a rocking shaft 89, which rock shaftunderlies the forward portion of the keyboard. The other end of thisrock shaft has an arm 90 connected by a link 91 to one arm 92 of a bellcrank lever pivoted at 93 and the other arm of which lever is bent toform a finger piece and indicator 94 which coacts with an indicatingde-' vice 95 on a bracket 96 secured to the side frame of the machine. Amovement of the finger piece 94 from one position to the other willtherefore shift the mechanism as desired, for addition or subtraction.

A short arm 97 is connectedby a spring 98 enclosing a plunger 99 to onearm 100 of a bell crank lever pivoted on a shaft 101 and having anupwardly and rearwardly extend ing arm 102 terminating in an offset 103.A shaft 104 at the rear of the computing mechanism carries a cam 105which is actuated by a pin 106 on the carriage, as clearly set forth inmy application Ser. No. 14,315. WVhen the shaft 104 is rotated on thereturn movement of the carriage a cam. 107 mounted thereon will engagethe; offset 103--:a'nd actuate the lever 102, thereby through theintermediate connections returning the lever to add position if-ithas'been previously-shifted to the subtract position.- This: insures'that. the mechanismv shall be in the add osit'ionwhen the next item iswritten in the etailed totalizer unless it is especially desired to movethe same to subtractpositionfor the purpose of entering aicredititemaWhen the totalizer' moves to the ground totahzer-positiomia earn 108engages aroller 109 on one arm 110 of a. bell crank leverl piv:- oted-at111-1- and having iiidownward extend- ;ing arm 1 12,connected byiwlink113 to :azlever -114 p1voted to-a stud'l15 carried :by the frameportion'ti; Atorsionalspring 116 on the stud has one endvsecuredtothe-frame- 6,

and the other'to the lever 114, and is so ten.- sioned as to force thehook 117 beneaththe lever 118.- The lower; end. 117 of this lever isformed as a hook and normally underlies the forward portion of-alever118 having a broad bearin 120 on the shaft-101 and normally urged in onedirection by a spring 119. This mechanism is generally similar to thatshown in my prior application. Ser. No. 14,315. The upper and rearwardlyextending arm of this lever 121 has an offset pin 122 for a purposehereinafterset forth. 7

As in my above entitled application the movement of the totalize'rto-thegrand totalher position is designed to operate themechanism justdescribed to allow the lore: 118 to be moved by the spring 119 and byits movement bring into operative position the error check mechanism. Inthe present case, however, provision is made whereby the error checkmechanism Willnot be brought into operative relation unless an item haspreviously been entered in the column totalizer. In such cases thetotalizer is moved directly to the grand totalizer position and sincethe number is being written for the first time, it is not necessary forthe error check mechanism to be in position. The following means istherefore provided for preventing the hook 117 from releas ng the lever118 unless an item has previously been entered in the column totalizcr.

The lever 1123 (Figures 4 and 13) is pivoted at 123' and has a forkedupper end 124 which embraces a pin 125 on the lever 29 which is actuatedeach time that a number is entered in the register. This lever has anoffset portion 126 terminating in a hook 127 which lies just in the rearof the lower portion of the hook 117. The lever 114 loosely pivoted onthe stud 1-15 and is normally drawn rearwardly by a spring 128 against astop member 129. If a number is written in the detailed totalizcr thelever 29 will be moved and thereby the lever 123 will be rocked to movethe lever 114 forwardly and bring the hook portion 117 slightly inadvance of its normal position. A thickened portion 130 on the lever 118is normally engaged by the hook 117 so that unless the hook has-beenpulled forward as just described, to a position in which it is clearofthe thickened portion 130, the rocking movement brought about by thetravelling register would not release the hook from the lever 118.Whenever an item has been written in the column totalizer, however, thebook will have been moved to a position in front of thethickened-portion 130 which will hold the lever 114 in its forwardposition so that-the subsequent rocking movement about thepivot 115 willrelease the hook fro'mth'e lever 118 and will cause the same to moveand-thereby bring into position the error check mechanism.-

When the lever 114 is drawn off the thickened portion 130 by the lever123, as'described above, the lever 118 drops under the force of thespring 119 until the lever 118 proper rests upon the hook 117. N ow,when the lever is released, the hook 117 cannot return to its originalposition, but will stop against the end of the plate lVhen the lever 118is released and moved downward under the influence 'of thespring 119 itrocks a bell crank lever pivoted at 132, the horizontal arm 133 of whichis engaged directly by the lever 118. This bell crank lever is carriedby a bracket 131 attached to the center frame 3 of the casing of theadding attachment. The vertical portion of the bell crank lever is intwo parts having arms 134 and 134 as clearly shown in Figure 4. The arm134 terminates in a rounded portion 135 which fits within the yoke 136having an upwardly extending arm 137 also shown in Figure 3. This armcarries a pin 138 which is adapted to engage an opening 139 in the sidemember 45 of the universal frame, heretofore described. The sidewisemovement which brings the pin 138 into the opening 139 thereforeconnects the universal frame which is actuated eaclr time that one ofthe sliding members 17 is moved with the arm 137 and causes the same tomove in 'unison therewith. The free end of this arm 137 is connected bya spring 140 which encloses a plunger 141 to the upper end of an arm 142which is pivoted by means of a pivot 143. Arms 144 and (see Figure 6)are also carried by the pivot 143 and move in unison with the arm 142whenever movement is communicated to the same. The front ends of thearms 144 and 145 engage the edge portion 146 o f'a frame 147 which has aplurality of upstanding flange fingers 148 each of which fingers has acut out149 arranged at a different portion of its vertical lengthj Eachsliding bar 17 has an offset 150 which when the frame 147 is in theposition'sliown in Figure" 6'moves idly between the-fingers biit whenthe frame is-fshifted to tha -left wfill contact with a flange ofth'fingr iinlessthe name has been raised to' a'posit-io'n'to, bring bne'ofl'the cut cuts 149 into l'egister with'the appropriate offset 150.- 1'1" f he frame'147 'tli'erfoi ef'supported for free up and downmovement, for a s'idewise shifting movement, 'andfb'r ei slight to andfro movement; is "guided between a. 151 and'an' oaseasrmylse 'oiralev'ei153 piv., otcd at 154' "any" forward (see Figure 3) 'bf'y 155- tanned atone end to said love and at its otherendt a fix ed accuses-i 2* if? Fiomthd far 'glven,"it evident n a elliifg ters-tliegrandonipiit'iligiionetIiecaiii IOS on? said regist "i'l'l eiigag-"tlie'-'rb11er 109 and through connections move the hook I17fr'oi'nengaging positidiilwith the lever 118, providing anm ber has previouslybeen written in .thc eoiu'iim regatta" In -this event the spririgll't)will for'ce' down the lever 1'18 rocking theibell crank which is pivotedat 132, thereby moving the lever 1137 sideivise' andconnecting the 'samewith; the universal frame which is actuated. by "thejsli ding bars 17.At the sainetimejthe downwardarm 134: of the bell crank lever will movesidewise the arms 144 and 145 which support the error check frame 147and move it to. a posi tion wherein the 0lt's'ets ,150"on the slidingbars 17 will. engagethe flanges of the 'upstanding fingers 148.".' Any'actuation of a numeral key thereafter will move a sliding bar 17 andthis movement will rock the universal frame 44 and through the'arm' 137,spring 140, lever 142, and levers 144 and145 will rock these leversaboutthe pivot 143 and more the error check frame 147 upwardly.

The distance through which thisframe is moved upwardly is determined bya link 162 which is connected to the cross piece 146 at one end and atits other end to a digit feelcr 163 pivoted at 37 and having an end 164which will contact with one or the other of a pair of pins 165 on anauxiliary wheel eared to the com iuting mechanism as set with in myprior application Ser. No. 14,315. If the proper key has been depressedthe end 164 will engage one of the pins 165 only when the frame 147 hasbeen raised sutliciently to allow the projection on the actuated bar 17to pass through the cut out 149 in the linger 148 which is adjacent thesame. A full actuation of the key will therefore. be permitted and theproper number will be printed and set up in the grand totalizer.

It, however, a wrong key is struck, the frame 147 will not be moved to aposition to permit the oflsct 150 to register with a cut out 1 19 butthis oil'set will come in contact with the flange of the adjacent finger148 and thereby rock the framel l'l' rearwardly. This rocking movementwill becommunicated to the lever 153 andwill move the upper end of thesame from underneath one end of a lever 158 pivoted -at 159 and normallytensioned in one direction by a spring 160. \Vhen this lever is releasedby a movement of the lever 153, the spring 160 will drawthe key end 4161of this lever upwardly moving the body of the lever between two adjacentballs 20 of the mechanism previously de scribed, which preventsdepression of more than one key lever at the same time.Therefor'e,if'the wrong key has been actuated, the key will beallowed tocomplete its full movement and return to normal position but theoperator will find that the mechanism is locked upon'a'n attempt'todepress the next following key. The errorwill therefore be calledto theoperators attention immediately afterits occurrence and can be correctedbefore subsequent figures are written. Whenever the error is corrected adepression of the key 161 will move the end 158 of the lever upwhereupon the spring will move the lever 153 back into position toretain this lever 158 in its normal inoperative position.

In the return movement of thecarriage which through the cam 105 rocksthe shaft 104, an arm 166 on this shaft will he brought into engagementwith the pin 122 and thereby rock the lever 118 back to a posltion inwhich it will be engaged by the detent 117 and held in its inoperativeposition. The various springs will thereupon return the parts to normalposition in which the error check mechanism is inoperative. A fiatspring-167 attached to the lower side of the lever 11S engages the underpart of the bell crank lever pivoted at 132 to move this back to normalposition, but to permit further movement of the lever 118 if it shouldoccur for any reason. A projecting pin 122 also al'l'ord means wherebythe operator can manually return the lever 118 to inoperative positionif so desired at any time.

It will be obvious from the above description that the mechanism hereindescribed may he used with computing mechanism of widely differing typesand that features of the invention can be used separately as well as incombination. The error check mechanism disclosed as well as the otherfeatures constituting the subject matter of this application, may beemployed in connection with clearance mechanism of the type shown ineither of my previous applications or with other types of mechanism. Itis obvious that the precise physical embodiment of the invention may hemodified widely without in any way departing from the spirit of theinvention. For these reasons, it is to be under stood that the inventionis to be regarded as limited only by the scope of the appended claims.

I claim:

1. A computing mechanism comprising a travelling totalizer, devices forentering numbers in said totalizer when it is in a certain zone, anderror check means rendered effective by a movement of the totalizer to adifferent zone which looks said devices immediately after the operationof entering an incorrect digit has been completed.

2. A computing mechanism comprising a travelling totalizer, keyoperated'devices for entering numbers in said totalizer when it is in acertain zone, and error check means rendered effective by a movement ofthe totalizer to a different, zone which looks said devices immediatelyafter the returnto normal position of an incorrect key.

3. A computing mechanism comprising a travelling totalizer, key operateddevices for entering numbers in said totalizer when it is in a certainzone, and error check means rendered effective solely by a. movement ofthe totalizer to a different zone which permits complete operation of anincorrect key but locks all keys immediately'thereafter.

4. A combined typewriting and computing mechanism comprising atravelling register having column and grand totalizers,-devices forentering numbers in either totalizer when it is in a computing zone, anderror check means rendered effective by a movement of the-grandtotalizer intothe computing zone which locks said devices immediatelyafter the operation of entering an incorrect digit has been completed.

5. A computing mechanism comprising a.

travelling totalizer, devices for entering run-n- .ers in said totalizerwhen it is in a certain Zone, error check means rendered effective by amovement of the totalizer to a different zone which locks said devicesinunediately after the operation of entering an incorrect digit has beencompleted, and means-tor autolcu lob

matically returning the error check means to ineffective position.

6. A computing mechanism con'iprising a travelling totalizcr, keyoperated devices for entering numbers in said totalizer when it is in acertain zone, error check means rendered effective by a movement of thetotalizer to a different zone which locks said devices immediately afterthe return to normal position of an incorrect key, and means forautomatically returning the error check means to ineffective position.

7. A computing mechanism comprising a travelling totalizer key operateddevices for entering numbers in said totalizer when it in a certainzone, error check means rendered effective solely by a movement of thetotalizer to a different zone which permits complete operation of anincorrect key but locks all keys immediately thereafter, and means forautomatically returning the error check means to ineffective position. v

8. A combined typewriting and computing mechanism comprising atravelling register having column and grand totalizers, devices forentering numbers in either totalizer when it is in thecomputing zone,error check means rendered effective by a movement of the grand.t'otalizerinto the computing z one which locks" said devicesimmediately after the operation of entering an-in'correct digit has beencompleted,andmeans for automaticallyi returning the error check means toineffective position. i I

i9; A "computing' mechanism comprising a travelling 'tot'al-izfer,devices for entering numberslin' s'aid totali'zer when it isin a certainzo'rie,e'rror chck'means rendered effective by; a movement'ojf thetotalizer to a different zone which locl s' aid devices immediatelyafter the 'opei ation of e ntering an incorrect digit. has beeneoi'npleted',y.ma manual means for moving the error check means toineffective position asdesii cd l I 'IOl "Acomputing mechanismcomprising a travelling totalizendevices for entering numbers in saidtotalizer'when it is in a certain zone,error check means which becomeeffective when thetotalizer moves to a second zone, and means whichprevents said error check means from becoming effective at that timeunlessa number has been entered in the first zone.

11. A computing mechanism comprising :1 tr velling register havingcolumn and grand totalizers, devices for entering numbers in eithertotalizer when it is in a computing zone, error check means which becomeefiective when the grand totalizer enters the computing zone, and meanswhich prevents the error check means from becoming effective at thattime unless a number has been entered just previously in the columntotalizer.

12. A computing mechanism comprising a travelling totalizer, devices forentering numbers in said totalizer when it is in a certain zone, errorcheck means which become effective when the totalizer moves to a secondzone, means which prevents said error check means from becomingeffective at that time unless a number has been entered in the firstzone, and means for automatically returning the error check means toineffective position.

13. A computing mechanism comprising a travelling register having columnand grand totalizers, devices for entering numbers in either totalizerwhen it is in a computing zone, error check means which become effective when, the grand tot-alizer enters the computing zone, meanswhich prevents the error check means from becoming'effect-ive at thattime unless a number has been entered just previously in the colunmtotalizer, and means for automatically returning the error check meansto ineffective position.

14. A combined typewriting and computing mechanism comprising atravellingcarriage, a travelling register having column and grandtotalizers', key actuated devices for entering numbers in eithertotalizer when it is in a computing zone, error check means normally inineffective relationtosaid de-- vices, and mechanism operated by themovement of theregisterto a position ,to bring the grand totalizer -intothe, computing zone which renders said error check means effective tolock said devices immediately after an incorrect'key has been operatedand has returned to normal position.

. .15. A. combined typewriting and computing mechanism comprising aftravelling. carrlage, a trayelling register havingcolumn and grandtotalizers, key .-jactuated devices; for entering numbers in; ,eithertotalizem when. it man a computing zone, err or check meansnormally ininefi'ective relation; to said devices,- meclianism' operatedkby -themovement of the register to a position tobring the grand tota-lizer into.the computing zone which renders said ,error check means efl'ective .tolock said devices immediately after an incorrectkey has been operatedand. hasreturned to normalrposition, and means which prevents saidmechanism from being effective unless a digit has previously beenentered in the column totalizer. v

16. A combined typewritingand comput-- ing mechanism comprising atravelling carriage, a travelling register having column and grandtota-lizers, key actuated devices for entering numbers in eithertotalizer when it is in a computing zone, error check means normally inineffective relation to said devices, mechanism operated bytheimo'vernent of the register to a position to bring the grandtotalizer into the computing zone which renders said error check meanseffective to lock said devices immediately after an incorrect key hasbeen operated and has returned to normal position, and means operated bythe return movement of the carriage to return the error check means toineliective position.

17. A combined typewriting and computing mechanism comprising atravelling carriage, a travelling register having column and grandtotalizers, key actuated devices for entering numbers in eithertotalizer when it is in a computing zone, error check means normally inineffective relation to said devices, mechanism operated by the movementof the register to a position to bring the grand totalizer into thecomputing zone which renders said error check means effective to locksaid devices immediately after an incorrect key has been operated andhas returned to normal position, means which prevents said mechanisn'ifrom being effective unless a digit has previously been entered in thecolumn totalizer, and means operated by the return movement of thecarriage to return the error check means to ineffective position.

18. A computing mechanism comprising a travelling totalizer, devices forentering numbers in said totalizer when it is in a certain zone, errorcheck meanswhich becomes effective when the totalizer moves to a secondzone, keys for operating said devicgs, and mechanism controlled by theerror check means for locking said keys iinmediately after thereturn"movement of an incorrectly depressed key. 7

19.- A computing mechanism comprisinga.- travelling register havingcolumn and grand totalizers, devices for entering numbers in eithertotalizer when it is in a computing zone,'error check meanswhidr becomeseffective when the grand totalizer enters -the;computing zone, meanswhich prevents the error check-means from becoming effective unless anumber has been enteredjust'previously in the Column totalizer', andmechanism controlled by the error check means for locking said keysimmediatel after the return movement of an incorrect y depressed key.

20. A computing mechanism'comprising a travelling totalizer, devices forentering nu inhers in said totalizer when it is in a certain zone, errorcheck means which becomeselfective when the totalizer moves to a secondzone,

keys for operating said devices, mechanism.

controlled by the error check means forlocking said keys immediatelyafter the return movement of an incorrectly depressed key, and means forunlocking said-keys.

21. A computing mechanism con'iprising a travelling register havingcolumn and grand totalizers, devices for entering numbers in eithertotalizer when it is in a computin zone, error check means which becomeseffective when the grand totalizer enters the computing zone, meanswhich prevents the error check means from becoming effective unless anumber has been entered just previously in the column totalizer,mechanism controlled by the error check means-for locking said'keysin'nnediately after the return movement of an incorrectly depressed key,and means for unlocking said keys.

22. A computing mechanism comprising a travelling register having columnand grand totalizers, key actuated devices for entering numbers ineither totalizer when it is in a computing zone, a universal frameactuated upon the depression of any key, error check.

means comprising a frame mounted for vertical movement and rockingmovement, and means for connecting the error check frame to theuniversal frame -when the grand totnlizel enters the computing zone.

23. A computing mechanism comprising a travelling register having columnand grand totalizers, key actuated devices for entering numbers ineither 'totalizer when it is in a computing zone, a universal frameactuated upon the depression of any key, error'check means comprisinga'frame mounted for vertical movement and rocking movement, means forconnecting the error check frame tothe universal frame when thegrand'tota'lizeri enters the computing zone, and' 'means for thereaftergiving the error-'clieck frame' its vertical movement whenever a key. isactuated.

24. A computing mechanism comprising a travelling register havinflcolunin and grand totali'zers, key actuated device's for enteringnumbers in either totalizer when it is in a computing zone, a universalframe actuated upon the depression of'any'lrey, error check meanscomprising a frame mounted for vertlcal movement and rocking-movement,-means for connecting-theerror checkgfranie to the un versal frame whenthe grand'totalizer enters the computing zone,"and meansforthere aftergiving the error che king;-

vertical movement' whenever a" 'lrey actu tedland giving it arock'irig'zmov'ernent Whenever an incorrect key isdepre'ssed.

25. A computing'm'echanism comprising a.

travelling register having column and. grand totalizers, key'actu'ate Il I numbers inweith e'r 'totalizer when-it 'isin"; i computing zone auniyersaliflrame actuated.

upon the depression ofany ke y, errorrcheck,

means comprising a' frame mounted for vert cal movement and rocking neinent, means. for connecting' the error check frame totlie universalframe when the grand totali'zer, en.- ters the computing zone, means forthereafter giving the error check' frameits vertical.

movement whenever a key is aetuatedzand giving it a rocking movementvhenever an incorrect keyisdepressed, andl'o'cking means; for said keysreleased whentheframeis given its rocking movementf 26. A computingmechanism comprising a travelling register having colunin and grandtotalizers. key actuated devices for entering numbers in eithertotali'zer'when it is in a computing zonc a universal frame actuatedupon the depression of'any key, error check "devices-for 'entering meanscomprising a frame mounted for vertical movement and rocking movement,means for connecting the error check frame to the universal frame whenthe grand totalizer enters the computing zone, means for thereaftergiving the error check frame its vertical movement whenever a key isactuated and giving it a rocking movement whenever an incorrect key isdepressed, locking means for said keys released when the frame is givenits rocking movement, and a key for restoring the locking means toineffective position.

27. A computing mechanism comprising a travelling register having columnand grand totalizers, key actuated devices for entering numbers ineither totalizer when it is in a computing zone, a universal frameactuated upon the depression of any key, error check means comprising aframe mounted for vertical movement and rocking movement, means forconnecting the error check frame to the universal frame when the grandtotalizer enters the computing zone, and means for automaticallydisconnecting the universal frame and the error check frame.

28. i A computing mechanism comprising a travelling register havingcolumn and grand totalizers, key actuated devices for entering numbersin either totalize'i when it is in a computing zone, a universal frameactuated upon the depression of any key, error check means comprising aframe mounted for vertical movement and rocking movement, meansforcconnectingthe error check frame to the universal frame when thegrand totalizer enters the computing zone, means for thereafter givingthe error check frame its vertical movement whenever a key is actuated,and means for automatically disconnecting the universal frame and theerror check frame.

29. A computing mechanism comprising a travelling register having columnand grand totalizers, key actuated devices for entering numbers ineither totalizer when it is in a computing zone, a universal frameactuated upon the depression of any key, error check means comprising aframe mounted for verti cal movement and rocking movement, meansfor-connecting the error check frame to the universal frame when thegrand totalizer enters the computing zone, means for thereafter givingthe error --check frame its vertical movement whenever a key is actuatedand giving it a rocking movement whenever an incorrect key is depressed,and means for automatically disconnecting the universal frame and theerror check frame.

30. A computing mechanism comprising a travelling register having columnand grand totalizers, key actuated devices for entering numbers ineither totalizer when it is in a computing zone, a universal frameactuated upon the depression of any key, error check means comprising aframe mounted for vertical movement and rocking movement, means forconnecting the error check frame to the universal frame when the grandtotalizer enters the computing zone, means for thereafter giving theerror check frame its vertical movement whenever a key is actuated andgiving it a rocking movement whenever an mcorrect key is depressed,locking means for said keys released when the frame is given its rockingmovement, and means for automatically disconnecting the universal frameand the error check frame.

31. A computing mechanism comprising a travelling register having columnand grand totalizers, key actuated devices for entering numbers ineither totalizer when it' is in a computing zone, a universal frameactuated upon the depression of any key, error check means comprising aframe mounted for vertical movement and rocking movement, means forconnecting the error check frame to the universal frame when the grandtotalizer enters thecomputing 'zone,means' for thereafter giving theerror check frame its vertical movement whenever a key is actuated andgiving it a rocking movement whenever an incorrect keyis'depressed,'locking' means for said keys released when theframe'isfgiven its rocking movement, a key for restoring the lockingmeans to ineffective positiom arid means for automatically.disconnecting the I universal frame and the-errorflcheckffra'me. 32. Acombined typewriting'andcomputing mechanism compris" a travelling riage,a travelling register iaving column and grand maiizers,reyacruatea=devic' for entering numbeis' "in'---- either rtotalizer' when itis in acomputing' zon'e', z'tuniver s al fiame actuated upon the depression ofedyflkey, error check means comprising amine mount ed for verticalmovement 'zind rocking mo'vement, means for connecting the error checkframe to the'univrs al'frame when, the-grand totalizer enters thecomputing' 'zohe, aiid means for preventing said-lconneotioiilunlss adigit has been entered just preyiousl y in column totalizer. v

33. A combined typewritin'g and computing mechanism comprisin atravelling carriage, a travelling registeriaving column and grandtotalizers, 'key actuated devices for entering numbers in eithertotalizer when is in a computing zone, a universal frame actuated uponthe depression of any key, error check means comprising a framefmojurited for vertical movement androeking move ment, means forconnecting the error "check frame to the universal frame .when the gra dtotalizer enters the computing zone,' means for preventing saidconnection unless digit has been entered just previously in thejcolumntotalizer, and means for giving the error check frame after connection avertical movement whenever a key is actuated.

34. A combined typewriting and computing mechanism comprising atravelling car- IOU riage, a travelling register having column and grandtotalizers, key actuated devices for entering numbers in eithertotaiizer when it is in a computing zone, a universal frame actuatedupon the depression of any key, error check means comprising a framemount ed for vertical movement and rocking movement, means forconnecting the error check frame to the universal frame when the grandtotalizer enters the computing zone, means for preventing saidconnection unless a digit has been entered just previously in the columntotalizer, and means for giving the error check frame after connection avertical movement whenever a key is actuated and a rocking movementwhenever an incorrect key is depressed. I

35. A combined typewriting and computing mechanismcomprising atravelling carriage, a travelling register having column and grandtotalizers, key actuated devices for entering numbers in eithertotalizer when it is in a computing zone, a universal frame actuatedupon the depression of any key, error check means comprising a framemount ed for vertical movement and rocking movement, means forconnecting the error check frame to the universal frame when the grandtotaliz er enters the computing zone, means for preventing saidconnection unless a digit has been entered just previously in the columntotalizer, means for giving the error check frame after connection avertical movement whenever afkey is actuated and a rocking movementwhenever an incorrect key is depressed, and lockingJmeans for the keysreleased when the frame is given its rocking movement.

36. A combined. typewriting and comput- 7 -an grand totalizers, keyactuated devices for entering numbers in either totalizer when it is'ina computing. zone, a, universal frame actuated upon the depression of aany key, error check means comprising a frame mounted for verticalmovement and rocking moveineiit, means for connecting the error checkframe to the universal frame when the grand total'mer enters thecomputing zone, means for preventing said connection unless a digit hasbeen entered just previously in the column 'totalizer, means forgivingthe error check frame after connectiona vertical movement whenevera keyis actuated and a rocking movement whenever an incorrect key isdepressed, locking means for the keys released when the rame is givenits rocking movement, and a key for restoring the looking means toineffective position.

37. A combined typewriting and computing mechanism comprising atravelling carriage, a travelling register having column and grandtotalizers, key actuated devices -for entering numbers in eithertotalizer when it is in a computing zone, a universal frame actuatedupon the depression of any key, error check means comprising a framemounted for vertical movement and rocking movement, means for connectingthe error check frame to the universal frame when the grand iotalizcrenters the computing zone, means for preventing said connection unless adigit has been entered just previously in the column totalizer, andmeans for automatically disconnecting the universal frame and the errorcheck frame by the return movement of the carriage.

38. A combined typewriting and computing mechanism comprising atravelling carriage, a travelling register having column and grandtotalizers, key actuated devices for entering numbers in eithertotalizer when it is in a computing zone a universal frame actuated uponthe depression of any key, error check means comprising a frame mountedfor vertical movement and rocking movement, means for connecting theerror check frame to the universal frame when the grand totalizer entersthe computing zone, means for preventing said connection unless a digithas been entered just previously in the column totalizer, means forgiving the. error check frame after connection a vertical movementwhenever a key is actuated, and means for vframe to the universal framewhen the grand totalizer enters the computing zone, means for preventingsaid connection unlessa digit has been entered just previously in thecolumn totalizer, means for giving the error check frame afterconnection a vertical movement whenever a key is actuated and -a rockingmovement whenever an incorrect key is depressed, and means forautomatically disconnecting the universal frame and .the error checkframe by the return movement of the carriage.-

. 40. A combined-typewriting and comput mg mechanism comprising atravelling carriage, a travelling register having column and grandtotalizers, key actuated devices for entering numbers in eithertotalizer when it is in a computing zone, a universal frame actuatedupon the depression of any key, error check mea ns comprising a framemounted for vertical movement and rocking movement, means for connectingthe error check frame to the universal frame when the grand totalizerenters the computing zone, means for preventing said connection unless adigit has been entered just previously in the column totalizer, meansfor giving the error check frame after connection a vertical movementwhenever a key is actuated and a rocking movement whenever an incorrectkey is depressed, locking means for the keys released when the frame isgiven its rocking movement, and means for automatically disconnectingthe universal frame and the error check frame by the return movement ofthe carriage.

41. A combined typewriting and computing mechanism comprising atravelling carriage, a travelling register having column and grandtotalizers, key actuated devices for entering numbers in eithertotalizer when it is in a computing zone, a universal frame actuatedupon the depression of any key, error check means comprising a framemounted for vertical movement and rocking movement, means for connectingthe error check frame to the universal frame when the grand totalizerenters the computing zone, means for reventing said connection unless adigit has been entered just previously in the column totalizer, meansfor giving the error check frame after connection a vertical movementwhenever a key is actuated and a rocking movement whenever an incorrectkey is depressed, locking means for the keys released when the frame isgiven its rocking movement, 9. key for restoring the locking means toineffective position, and means for automatically disconnecting theuniversal frame and the error check frame by the return movement of thecarria e.

42. A computing metihanism comprising a travelling'register havin columnand grand totaiizers, key actuated devices for entering numbers ineither totalizer when it is in acomputing zone, an error check framemounted for sidewise movement, vertical movement, and rocking movement,and means for giving the error check frame its sidewise movement whenthe grand totalizer enters the computing zone.

43. A computing mechanism comprising a travelling register having columnand grand totalizers, key actuated devices for entering numbers ineither totalizer when it is in a computing zone, an error check framemounted for sidewise movement, vertical movement,-and rocking movement,means for giving the error check frame its sidewise movement when thegrand totalizer enters the computing zone, and means for thereaftergiving the error check frame a vertical movement upon the depression ofa numeral key.

44. A computing mechanism comprising a travelling register having columnand grand totalizers, key actuated devices for entering numbers ineither totalizer when it is in a computing zone, an air check framemounted for sidewise movement, vertical movement, and rocking movement,means for giving the error check frame its sidewise movement when thegrand totalizer enters the computing zone, means for thereafter givingthe error check frame a vertical movement upon the depression of anumeral key, and means for giving the error check frame its rockingmovement if an incorrect key is depressed.

45. A computing mechanism comprising a travelling register having columnand grand totalizcrs, key actuated devices for entering numbers ineither totalizer when it is in a computing zone, an error check framemounted for sidewise movement, vertical movement, and rocking movement,means for giving the error check frame its sidewise movement when thegrand totalizer enters the computing zone, means for thereafter givingthe error check frame a vertical movement upon the depression of anumeral key, means for giving the error check frame its rocking movementif an incorrect key is depressed,

and means for locking the keys which-is released when the frame is givenits rocking movement.

46. A computing mechanism comprising a travelling register havingcolumn'and grand totalizers, key actuated devices for entering numbersin either totalizer when it is in a computing zone, an error check framemounted for sidewise movement, vertical movement, and rocking movement,means for giving the error check frame its sidewise move ment when thegrand totalizer enters the computing zone, and means for automaticallvrestoringthe error check frame to ineffective position. I

47. A computing mechanism comprising a travelling register having columnand grand totalizers, key actuated devices for entering numbers ineither totalizer when it is in a computing zone, an error check framemounted for sidewise movement, vertical movement, and rocking movement,means for giving the error check frame its sidewise movement when thegrand totalizer enters the computing zone, and mechanism for preventingsaid means from operating unless a digit has been entered justpreviously in the column totalizer.

48. A computing mechanism comprising a travelling register having columnand grand totalizers, key actuated devices for entering numbers ineither tot-aiizer when it is in a computing zone, an error check framemounted for vertical and rocking movements, means for giving said frameits vertical movement only when the grand totalizer is in the computingzone, and means for determining the extent of movement of said frame bythe numbers previously set up in the column totalizer.

49. A computing mechanism comprising a travelling register having columnand grand totalizers, key actuated devices for entering numbers ineither totalizer when it is in a computing zone. an error check framemounted for vertical and rocking movements, means for giving said frameits vertical movement only when the grand totalizer is in the computingzone, means for determining the extent of movement of said frame by thenumbers previously set up in the column totalizer, and means for rockingsaid frame to release locking mechanism for the keys if an incorrectdigit is entered in the grand totalizer.

50. A computing mechanism comprising a travelling register having columnand grand totalizers, devices for entering numbers in either totalizerwhen it is in a computing zone, keys for actuating said devices, lockingmeans for preventing depression of said keys Whenever an incorrect digithas been entered in the grand totalizer, and mechanism for preventingsaid locking means from becoming efi'ective unlessa digit has justpreviously. been entered in the column totalizer.

51. A computing mechanism comprising a travelling register having columnand grand totalizers, devices for entering numbers in eithertotalizerwhen it is in a computing zone, keys for actuating saiddevices, error check means for preventing the writing of a wrong numberin the grand totalizer, a lever for moving said error check means tooperative position, a detent for retaining said lever against movement,and means for movingsaid detent in two directions to release said lever.

52. A computing mechanism comprising a travelling register having columnand grand totalizers, devices for entering numbers in either totalizerwhen it is .in a computing zone, keys for actuating said devices, errorcheck means for preventing the writing of a wrong number in the grandtotalizer, a lever for moving said error checklmeans to opera tiveposition, a detent for retaining said lever against movement, means formoving said detent in two directions to release said lever, meansoperated by the entry of-a digit .in the column totalizer to move saiddetent in one direction, and means operated by the move ment of thegrand totalizer into the computing zone to move the detent in the otherdirection and release said lever.

53. A computing mechanism comprising a travelling register having columnand grand totalizers, devices for entering numbers in either totalizerwhen it is in a computing zone, keys for actuating said devices, errorcheck means for preventing the writing of a wrong number in the grandtotalizer, a lever for moving said error cneck means to operativeposition, a detent for retaining said lever against movement, means formoving said detent in two directions to release said lever, a spring foractuating said lever, and automatic means for returning the lever toine'llective position.

54. A computing mechanism comprising a traveling carriage, a travelingregister navcolumn and grand totalizers, devices -for entering numbersin either totalizer when it is in the computing zone, keys for actuatingsaid devices, and locking means for prevcnt ing depression of said keyswhenever an incorrect digit has been entered in the grand totalizer saidcarriage being free to move when said locking means is operated.

55. A computing mechanism comprising a traveling carriage, a travelingregister having column and grand totalizers, devices for enteringnumbers in either totalizer when it is in the computing zone, keys foractuating said devices, locking means for preventing depression of saidkeys Whenever an incorrect digit has been entered in the grandtotalizer, and a key for restoring said locking means to inefi'ectiveposition said carriage being free to move when said locking means isoperated. 56. A computing mechanism comprising a travelling registerhaving column and grand totalizers, devices for entering numbers ineither totalizer when it is in a computing zone, keys for actuatingsaiddevices, error check means for preventing the writing of a wrongnumber in the grand totaiizer, a lever for moving said error check meansto operative position, a detent for retaining said lever againstmovement, means for moving said detent in two directions to release saidlever, means operated by the entry of a digit in the column totalizer tomove said de-tent in one direction, means operated by the movement ofthe grand totalizer into the computing zone GUSTAVE O. DEGENER.

